1. Field of the Invention
This invention relates to an extraction cleaning. In one of its aspects, the invention relates to an upright extraction cleaning machine having a flow rate indicator for cleaning solution.
2. Description of Related Art
Upright extraction cleaning machines have been used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. The known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or an upright unit as disclosed in U.S. Pat. No. 5,937,475 to Kasen et al.
The state of the art for water extraction cleaning machines utilizes one of two different technologies. First, water is mixed with a cleaning detergent and the resulting solution is sprayed onto the surface to be cleaned. The detergent includes chemical agents adapted to enhance the cleaning performance and dirt attraction of the cleaning solution. The vacuum motor is used to create a source of suction for withdrawing the cleaning solution and entrapped dirt back into the cleaning machine.
Cleaning solution is dispensed to a spray nozzle, in some cases through a pump, or by gravity flow. It is not clear to the operator how much, if any, cleaning solution is dispensed to a spray nozzle.